Raytheon Beech Baron E55 - Page 620

RayNheon
nircraft
Company
BARON
55
AND
58
SHOP
MANUAL
ALTERNATOR
CONTROL
UNIT
ADJUST
(BENCH
CHECK)
To
properly
adjust
the
alternator
control
unit
on
the bench
the
following
equipment
is
required:
1.
A 28
vdc
regulated
power
supply.
2.
A Precision
voltmeter
(0-50
volt
range,
1%
accuracy).
3.
A
dummy
resistance
load
(4 ampsj.
4.
An
ammeter
(0-5A
range).
5.
A
contactor
indicator
device.
(A
small
28
vdc
relay,
or a
28 vdc
indicator
lamp,
or a
voltmeter.)
6.
Oneconnector
(AMP-206708-1).
The
alternator control
unit
is
adjusted
as
follows:
I
a.
Set
up
test
configuration
(Ref. Figure 4).
b.
Jumper
the
power
supply
positive
lead
to
the
ammeter
positive
lead.
c.
Turn
the
power
supply
ON
and
set
the
output
to
28.5
vdc.
d.
Adjust
the
dummy
load to obtain
a
4
amp
reading
on
the
ammeter.
e.
Turn
the
power
supply
OFF
and
remove
the
jumper.
f.
Mate the
test
connector
to
the alternator control
connector.
I
g.
Turn
the
power
supply
ON and
adjust
the
output
to
28.5 vdc.
NOTE:
Hold
this
voltage
constant.
The
contactor
indicator
device
should indicate ON
when
power
is
applied.
h.
After
a
2
minute
warm
up
period,
adjust
the alternator
control unit
as
required
to
obtain
1.0
amp
load
indicated
on
the
ammeter.
NOTE:
While
performing
the
following
step, only
one
precision
volt
meter
is
required.
The
input
voltage
does
not
need
to
be maintained
at
any
precise
value,
and
the
same
voltmeter
may
be used for
both
tests.
i.
With
the
1.0
amp
load
indicated
on
the
ammeter,
the
equalizer
voltage
should be
5.75 0.1
vdc.
j.
Turn
the
power
supply
OFF
and disconnect
the
test
setup.
NOTE:
1
Deviation from
the
normal
value
(5.75 volts)
might
be due
to voltmeter
calibration
differences,
temperature
variations
or
ageing
of
the unit
under
test.
2.
Equalizer
voltage
failing
outside
the
5.65 5.85
limit is
not
necessarily
a cause
for
rejecting
the
unit.
3.
The effect
of
large
equalizer
voltage
variation
will
be
a
tendency
of
the
current balance
to
be
offset
when
the
unit is
operating
as a
companion
unit
in
a
complete
airplane
system.
4.
The
expected
load
current
offset
is
about
1.0
amps
for
a
0.1 volt
difference
in the
equalizer
voltages
of
two
alternator
control
units
operating
together
in
an
airplane
system.
Such
a
small load
balance
difference
would
be
difficult
to
verify
in
a
field
test
facility.
5.
If
the
equalizer
voltage
is
substantially
outside the
indicated
range
(for
example,
several
times
the
tolerance),
the
unit should
be
rechecked
in
a
fully
equipped
test
facility.
Dec
31/03Page
22
SECTION
13
E21